The Properties of White Mineral Trioxide Aggregate (WMTA) Made of Rice Husk Ash Silica and Limestone Calcium Carbonate and the Effect of Silica Particles Addition

Abstract

White Mineral Trioxide Aggregate (WMTA) using a combination of precursors consisting entirely of SiO2, CaCO3, Al2O3, and Bi2O3 which are widely used as cement for tooth restoration has been prepared. SiO2 was extracted from rice husk ash containing about 85-95% of silica found in rice husk ash from complete combustion. On the other hand, rice husks, in general, are still regarded as agricultural waste resulting from the rice milling process. In the rice milling process, around 20-30% of rice is obtained, and around 14-20% of ash is produced from burning rice husks. CaCO3 can be synthesized from limestone and it contains about 95% calcium carbonate. In this research, the researcher made WMTA from rice husk silica and CaCO3 from limestone. This research was carried out in several stages of silica extraction from rice husk ash using the high-purity sol-gel method, then the synthesis of calcium carbonate with the carbonation method obtained precipitated calcium carbonate (PCC). Preparation of WMTA by reacting silica sonicated + PCC + Al2O3 accompanied by stirring and heating 85 °C for 24 hours for homogenization, gelation, and maturation processes will be obtained by MTA’s gel. The MTA gel dried and calcined 1000 °C for 3 hours to obtain a white powder, the final product was added Bi2O3 of 18% produced high-quality WMTA. The results of making WMTA and modification silica of rice husk ash and PCC from limestone were characterized using XRD, FTIR showed characters that had similarities with WMTA ProRoot and had better diameter tensile strength test capabilities.